


place in my heart

by orphan_account



Category: Undertale (Video Game)
Genre: 1000000 PERCENT MUSH, Cuddling, Fluff and Smut, Gender-Neutral Pronouns, Light Bondage, Other, Post-Pacifist Route, Reader Is Not Frisk, Sensitive bones, Sub Sans, bonding over puns
Language: English
Status: Completed
Published: 2015-11-30
Updated: 2015-11-30
Packaged: 2018-05-04 06:16:05
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,540
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5323646
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>You’ve known Sans just long enough to be able to recognize his poker face on sight, but not quite long enough for him to take it off around you, and you know it shouldn’t hurt, but it does.</p>
            </blockquote>





	place in my heart

**Author's Note:**

> i cant believe im writing a fanfic for the first time in like 10 years and its fuckign skeleton porn

You’ve known Sans just long enough to be able to recognize his poker face on sight. The most distressing thing you’ve learned since you realized you could do this is just how often he wears it. 

Of course you know he’s not always okay, even when he says he is; you’ve felt his fingers grasp at the front of your pajama shirt and his shaking body pressed flush against your back in the middle of the night as you pretended to sleep, unsure what to say; you’ve turned to face him in the kitchen, flour covering your hands, and though his face barely flickered you were close enough to feel the beat his heart skipped before he passed you the spatula. You’re not sure what he’s remembering. He’s never told you. Maybe he never will. But that’s okay. Everyone has their secrets, right?

But sometimes, even on the days when everything seemed okay, when he was cracking terrible jokes and chatting up the room at New Grillby’s and grinning ear to ear like always, that smile didn’t quite reach the lights in his eyesockets, and you could almost see the corners of his mouth tremble, just this side of perceptible, as he willed them to stay up. But still, every time you tried to ask what was going on, if he was really okay, he’d brush it off, redirecting the conversation effortlessly until you almost forgot why you’d brought it up in the first place. Almost.

You’ve known Sans just long enough to be able to recognize his poker face on sight, but not quite long enough for him to take it off around you, and you know it shouldn’t hurt, but it does. 

But then again, it makes the moments when he’s not wearing a mask that much sweeter. You now know that the way his face lights up with pride and affection when his brother serves him a plate of his (admittedly improving) pasta or when he tells him about his latest adventures as a school crossing guard is totally genuine. And back when you took him up into the mountains with his good telescope, making him ride blindfolded in the shotgun seat despite his goodnatured protests, the look of wonder on his face and the soft glow of his blush when you took the blindfold off and showed him the Milky Way for the first time was something you wanted to put into a box and keep forever. It planted something warm and blooming in your heart. Something hungry. You want to see that face again (flushed, mouth wide open). You want to see him look at you with the same unguarded awe and wonder as when he first saw the stars, like you’re the only thing in the world and the most precious to him (as he writhes under you, begging you to please, please-)

This train of thought is going downhill awfully quickly.

Luckily, here you are, perched on his bare ribcage, winding a red silk rope between his radius and ulna and tying his wrists to the headboard of your bed with a firm knot. Scouts and anatomy class had been good for something after all! You watch a little nervously as he tests the bonds, half worried that he’ll-

“worried I’ll pop out one of my wrist bones with the rope or something, huh?”

You know Sans is good at reading people but sometimes it borders on goddamn telepathy and it really stresses you out. His ribcage rattles softly under you as he chuckles at your presumably perplexed expression. You blush at the sensation. Not yet.

“don’t worry, pal. these guys aren’t going anywhere.”

He pulls on the ropes to demonstrate, and sure enough, whatever magic is holding him together is strong enough to keep all his bones firmly in place.

“nope. no bones are gonna be popped tonight. actually, y’know…”

His eyelids lower slightly (eye sockets? you still don’t know how the fuck he does that) and he shoots a meaningful glance down at his pelvis.

“maybe just one.”

You stare down at him, puzzled. That must have been some kind of dirty pun. Right? Do skeletons like having their pelvis bones popped? How does that--Oh!

“It’s bon-ER, Sans. Popping a boner. That’s the expression.”

His grin doesn’t budge, as per usual, but his face flushes a little more and the lights in his eyes refuse to meet yours. You feel a little bad for laughing.

“oh. uh. well. heh. y’know.”

There’s a sudden, heavy silence between you two, but before you can open your mouth to apologize he fixes you with an expression that would look very serious on anyone else.

“i don’t have. genitals.”

Beat.

You both crack up in unison, mercifully breaking the nervous tension in the room as you shimmy down his body enough to lay on top of him comfortably, resting your head in the crook of his collarbone.

“Somebody’s off their pun game today.”

“c’mon, can you blame me? i’m a little, ah, a little t-tied up, at the moment-”

His breath stutters beautifully as you trace your fingertips feather-light along the inside edges of his arm bones. It’s not your first time together, but until now it’s usually been him pinning you down and not the other way around, reducing you to a quivering mess before you really had a chance to return the favor. You realize he might not be used to being touched like this, and you pull back for a moment, studying his expression to make sure his reactions are from pleasure and not nervousness. He stares back up at you, suddenly seeming impatient, and relief washes over you as you decide it’s mostly the former. Of course, there’s no way you’d get a straight answer out of him if you just asked if he was nervous, but you’ll do your best to help him relax anyway. You lean in close, cupping his cheekbones, forehead inches from his.

“You remember the safe word, right? ‘Yellow’ to slow down, ‘blue’ to stop, okay?”

The corners of Sans’s mouth are still quivering a little bit, but his eyes are warm as he lets go of a shaky breath and closes the distance, touching his forehead gently to yours in what you’ve been told is the skeleton version of a kiss. Your heart swells.

“what’s the color for ‘hurry up and take me to the bone zone already’? i’ll have that one.”

“Coming right up!”

You smile and plant another kiss (the human version) on his forehead, then another on his round cheekbone, trailing down over his lips (another aspect of skeleton anatomy you aren’t going to think too hard about) to his jaw. Meanwhile, your hands wander south, coming to rest on his sternum, fingertips teasing the places where his ribs begin. He hums contentedly. You proceed. Feeling a little braver now, you dip into the gaps between his ribs, curling around them and stroking the undersides lightly, back and forth. His contented hum turns into a long exhale and he shifts underneath you. You move faster, applying more pressure until his breath hitches and-

“ah-”

His hands curl and his elbow jerks as he pulls at the rope, reflexively trying to stifle the sound before it comes out. You glance up and see him flush harder, his smile slipping, cheeks glowing blue. A grin tugs at your lips and you feel something warm prickling at the base of your spine. You whisper against the vertebrae of his neck.

“Louder.”

Not giving him time to react, you rest one of your hands inside his ribcage, stroking your palm firmly down the ridges of his spine. His back arches up to meet your touch and soft noises threaten to escape his closed lips. He’s almost like a cat, you think, and despite your attempts to be serious and sexy you find yourself smiling as his eyes flutter closed and his brow ridges furrow.

“You’re really cute, you know that, Sans?”

“s-shut it- mmn!”

He cuts off his own flustered complaint with a moan. You’re cupping the underside of his thigh bones now, lifting them as if they were weightless, stroking upwards and inwards. He lifts his hips in anticipation, but he doesn’t seem quite frustrated enough for you to give him what he wants. You want to see how much more desperate you can make him. His jaw falls open in a sigh when you circle your fingers around to hold his hipbones up to yours and doesn’t close again. He’s full-on panting, now, shaking slightly in your hands, and when you roll your hips against his the breathless gasp he lets out goes straight to your crotch.

“Ooh, someone’s eager.”

“speak for… hah… yourself…”

You bite your lip and push his hipbones against the bed, away from you. He’s right. The throbbing between your legs is beginning to get unbearable, and if you start you know you won’t be able to stop. He pushes back against your hands, searching for friction, but you don’t budge, outlining the shapes of his hipbones with your fingertips.

“ahh, d… damnit, kid… stop teasing me already…”

His hands open and close uselessly above his head, which had lolled to the side at some point, a small amount of drool escaping his open mouth. The luminescent blush that had spread across his cheeks earlier had creeped all the way down to the top of his collarbone, faintly illuminating the sheets around him with a soft blue light. You’ve never seen him so wrecked before. It’s equal parts endearing and arousing. You drink in the sight of him, committing the image to memory.

“Well, you know what they say…”

You grasp his spine and move your hand lazily up and down. He writhes against the bed, a moan on the back of every exhale. You grasp his chin with your free hand, gently but firmly turning his head toward yours. Not without some effort, he opens his eyes, and you almost forget the pun you were about to use. His expression is mesmerizing. Brow ridges furrowed and twitching slightly, mouth open and panting. His eyes, gazing up at you like you’re the only thing in the world and the most precious. Starstruck. Your heart skips a beat, and you can’t stop yourself from leaning in and kissing him softly. Kissing him is like making out with a rock with lips and it’s not something you’d ever thought would turn you on and yet. Here you are. You continue with the pun you’d started earlier.

“It’s about the journey… not the dickstination.”

His face goes slack with shock for a moment. You almost start to worry that you’d offended him somehow until he breaks out into a grin, a real, genuine smile. Your knees go weak.

“oh my god… i think i love you.”

Immediately, he somehow blushes even harder and starts furiously backpedaling.

“uh. u-um, i mean-”

“Sans.” 

“i don’t wanna make you feel like you. have to or. i-”

You kiss him again. He goes quiet.

“Sans. It’s okay. I… I love you too, okay?”

Slowly, the smile comes back to his face, softer this time, with an air of relief. Your hand, still on his spine, moves absently. He twitches.

“ah- listen, can we maybe talk about this when you’re not all up in my vertebrae? heh heh- hhh- ahn-”

For once, you’re way ahead of him, slowly but surely making your way down to his pelvis.

“That sounds good to me. I don’t plan on you being able to talk any time in the near future anyway.”

You feel him shudder, taking the time to savor it before you move on to rubbing circles into the dips in the front of each hipbone with your thumbs. He throws his head back on the pillow and groans.

“god, yes, please… please…”

How can you say no when he asks so nicely? Finally, you move over his pubis with a firm downward stroke, tracing the inside edge of his pelvic cavity. He bucks roughly into your hand with a strength that surprises you. He must already be close from all the teasing. You press hard at the spot at the base of his spine that you know he likes, and he all but screams.

“hah- fuck, i-i’m-”

You’ve never really gotten the chance to watch him this closely as he comes. It’s not like you can see his muscles tighten, obviously, but you can still see the wave of tension starting from his toes and moving upward, crashing over him, making him shake so hard you’re almost afraid he’ll come apart. You watch his eyelids flutter as he chants your name like a prayer until it comes out a jumbled mess of moans and praise and pleas to never, ever stop. And you don’t, refusing to let up until the movement of his hips slows and his body goes slack, sinking into the sheets, and his moans turn into overstimulated whimpers. That was even quicker than you’d expected. 

Taking care not to brush too hard against any more sensitive spots, you disentangle your hand from his pelvis and set to work untying him. He twitches as the silky rope brushes against the inside of his wrists. As soon as he’s free, he latches onto you like the world’s boniest koala, burying his face into your chest and dragging you down onto the bed with a soft, fluffy thump. Surprised, you just manage to roll over to the side to avoid falling on him. You smile, circling your arms around him and rubbing soothing circles into the back of his skull.

“do you… want me to…” he mumbles against you, felt more than heard. 

You shake your head until you realize he can’t see you.

“No, don’t worry about it. Next time.” 

Somehow, you already feel satisfied, if in a different way. Besides, you know he’ll be out in a matter of minutes. You end up thinking back to the time he fell asleep with his fingers still inside you and can’t stop yourself from laughing. To your surprise, he laughs too. It’s not his usual deliberately placed, impeccably timed, chuckle, but a soft sound almost like a whisper, like warm secrets bubbling up from his chest through his mouth. You hook your leg around his knee and pull him closer.

“What are you laughing at?”

“nothin, ‘m just… happy…”

Your heart feels like it might burst. You curl in and kiss the crown of his skull. He responds with a soft snore.

“Me too, Sans. Good night.”

There’s one thing on your mind, after you pull the covers up around you both and start drifting into sleep yourself, radiating in the soft warmth his bones give off and the way his body nestles perfectly into yours. You’ve known Sans just long enough to be able to recognize his poker face on sight. Maybe not long enough for him to never wear it around you. Maybe no one would ever know him long enough for that. 

But you knew that when he told you he loved you, that was for real, and that was what you needed the most.

**Author's Note:**

> thanks to my friends and bf who encouraged me to write this it was worth it even tho im going to hell now UR ALL COMING WITH ME


End file.
